Machine for producing asbestoscement pipes



Jam 20, 1948. FERLA MACHINE FOR PRODUCING ASBESTOS-CEMENT PIPES Original Filed Oct. 19, 1939 5 Sheets-Sheet 1 Jan. 20, 1948. J. FERLA 2,434,690

MACHINE FOR PRODUCING ASBESTOS-CEMENT PIPES Original Filed Oct. 19, 1939 3 Sheets-Sheet 2 fiyygzzazi" J'o 22' er a [y M Jan. 20, 1948. J. FERLA MACHINE FOR PRODUCING ASBESTOS-CEMENT PIPES Q MF w a y mw mw WM w l HAHN H 1W 6 W Sm a 6 VJ n aw y J HIIHMW {I l l i m k Q Patented Jan. 20, 1948 UNITED STATES PATENT OFFICE MACHINE FOR PRODUCING ASBESTOS- CEMENT PIPES Jersey Original application October 19, 1939, Serial No.

Divided and this application March 7, 1944, Serial No. 525,448

9 Claims.

This application is a division of my application on Machines for producing pipes, Ser. No. 300,275, filed October 19, 1939, now Patent No. 2,374,086, granted April 17, 1945, which in turn Was a continuation-impart of my prior app ication on Method of producing tubes, Ser. No. 184,509, filed January 12, 1938, now Patent No. 2,177,643, granted October 31, 1939.

This invention relates to the manufacture of asbestos cement pipe, such as is made from a mixture of Portland cement and asbestos fibers mixed together and formed into a mass of plastic material.

It has been the practice heretofore to manufacture asbestos cement pipe by the accumulation of a layer or layers on a mandrel until the desired thickness is made, after wh ch the material is dried and treated until the mass hardens and sets.

The object of this invention is to improve the manufacture of such asbestos cement pipe by eliminating the necessity for rolling no the layers on the mandrel, and instead, producing the pipe in a continuous manner, by mixing the material and extruding the same in the form of a tube. The material is forced preferably into a mold around a, mandrel where it is formed in the proper and desired shape to produce a pipe of the required length. The pipe may be made in this way with a bell collar, although the mandrel and mold are not required necessarily, if the pipe is to be made in continuous uniform size.

The invention contemplates the provision of an extrusion device including a screw operatively mounted in a casing for extruding the material therefrom in the form of a tube, provision being made for uniformly working the plastic mass to distribute the fibers through the cementitious material during the extrusion process.

Another feature of the invention resides in the provision of a mold and mandrel combined adapted to form the pipe with a bell collar thereon when plastic material, such as a mixture of asbestos and cement, is forced under pressure into the mold. This provides for the shaping and forming of the pipe in a simple and effective manner, and yet provides a pipe of the required shape and density of structure which will be effective for many uses to which asbestos cement pipes are capable of being applied.

The invention is shown applied in the accompanying drawings in which:

Fig. 1 is a longitudinal section of the extrusion apparatus for forming the pipe; 1

Fig. 2 is a vertical cross section therethrough on the line 2-2 of Fig. 1;

Fig. 3 is a longitudinal sectional view of a modified form of extrusion apparatus;

Fig. 4 is a vertical cross section therethrough on the line 4-4 of Fig. 3;

Fig. 5 is a detail edge view of the demountable ring used in forming the tube, removed from the apparatus;

Fig. 6 is a side elevation of the assembly of apparatus for molding and compressing the pipes;

Fig. 7 is a longitudinal sectional view through the compression machine; and

Fig. 8 is a similar view through the hydraulic power device used in connection therewith.

Referring first to Fig. 6, this shows the assembly of an extrusion device associated with molding apparatus in which pressure may be applied to the formed or molded pipe hydraulically or by other fluid power. The hydraulic power device is here designated generally by the numeral and is associated with a molding device indicated at 65, provision being made for feeding the plastic material such as a mixture of asbestos fibers and cement, into the molding device for shaping and forming such mass into a pipe of the required shape and size.

The molding apparatus is shown in detail in Fig. 7, where this apparatus is shown as provided with a casing 66 having an internal cavity of the general outline of the, tube to be formed, including a bell collar on the tube. The casing 66 is supported on standards 61 connected together through tie rods 68.

A mandrel is shown at 36 suitably mounted within the chamber of the casing 56. i'fihe mandrel 36 is shown as of tubular form and radially perforated to allow the moisture to pass through the wall of the mandrel from the material under compression therearound. When it is desired to make a. pipe with a bell collar on one end thereof, the mandrel 35 should be formed with an enlarged bell portion at one end of a size substantially to shape the inner surface of the bell end of the pipe. The periphery of the pipe is shaped by the inner cavity or chamber formed in the casing (it.

A vacuum tube 69 extends to the rear end of the chamber or cavity formed in the casing 66, and has a branch pipe 10 controlled by a valve 1|, extending to the forward end of the casing chamber. Also connected with the casing chamber at a side thereof is a pipe '12, provided with a control valve 1'3, to admit air or water into the casing when desired by the operator.

aesaeso A hollow piston I4 is slidably mounted in the inner end of the cavity of the casing 66, and is preferably of slightly smaller diameter than said chamber. The piston I4 is mounted on and secured to a piston rod I5 which is hollow and extends outwardly through a stufing box in one end of the casing 66. The hollow piston rod I5 surrounds another piston rod 76 which projects into the piston I4. The forward end of the piston rod I6 has secured thereon a piston 11 which has a diameter sufficient to contact with the surrounding wall of the mandrel 36 at one end of said mandrel, as shown in dotted lines in Fig. 7.

The pistons I4 and I1 are operated by a hydraulic power device 68 shown generally in Fig, 8. The hydraulic power device is provided with a cylinder 18 in which a piston I9 is operatively mounted and connected with the piston rod I5. The piston I9 is operated by hydraulic pressure admitted into the cylinder I8 through a pipe 88 at one end of the cylinder, leading to a control valve 8| from which a pipe 82 also leads to the opposite end of the cylinder 18. The valve 8I controls the admission of fluid alternately through the respective pipes 80 and 82 for causing reciprocating movement of the piston I9.

The piston rod I6 extends through the cylinder I8 and into a cylinder 83 where it is connected with a piston 84. Pipes 85 and 86 are connected with opposite ends of the cylinder 83, extending to a control valve 81. A pipe 88, connected through a fitting 89 with a source of hydraulic pressure 90, leads to the respective valves BI and 81 for supplying hydraulic pressure thereto.

The plastic material is adapted to be forced into the casing 66 between the latter and the mandrel 36, as shown at P in Fig. 7. It will be noted that the mandrel 36 slidably fits into the hollow piston 14, whereby the piston closes one end of the plastic space. The mandrel 35 is supported at its opposite end by a perforated ring 9| which is inserted into the space between the mandrel 36 and the inner chamber 66, after the plastic material has been applied thereto, which ring 9| is slightly smaller in external diameter than the diameter of the chamber in the casing 66, and also perforated, for the passage of water through the wall of the ring.

The outer end of the chamber is closed by a. removable plate 92 fitted thereover and sealed by a packing ring 98, the plate 92 is held in place by a removable door 94 secured to the end of the casing by screws 98, as shown in Fig. 7.

When the compression device is being used to form a pipe, a ring I 4'! is inserted into the end of the casing 56, in place of the ring 9|, The ring I4l (shown in Fig. 1) is provided with spaced lugs I48 bearing upon a disc I49 fitted into the enlarged end of the mandrel 36, closing said mandrel.

The compression device shown in Figs. 1 and 2 comprises an extrusion device including a hopper I-I supported upon a casing I34. The casing I 34 is mounted on wheels I35 adapted to travel on rails I 36, so as to be moved into and out of align-, ment with the molding device described above, whenever desired. The hopper H is adapted to receive the plastic mixture to be used in forming the pipe.

Extending transversely of the casing I34, at the bottom of the hopper H, is a pair of rollers I31 formed with longitudinal bars or ribs I38 which interfit with each other, as shown in Fig. 2. Upon rotation of the rollers I31, the bars or ribs I38 feed the material positively downward from the hopper into the casing I 34, and into the feed screw I42.

The chamber I39 is closed at one side while the opposite end of the casing is reduced in diameter to form a narrow passage I45 which is connected with the enlarged portion of the chamber through a conical slope or passage I44. As material is forced lengthwise of the chamber I39 and through the conical passage I44, and the constricted passage I45, the material is compressed before it is fed into the mold.

Extending lengthwise through the chamber I39 is a shaft I46, which projects also into and substantially through the constricted portion I45. The shaft I40 has a sectionized screw conveyor I42 mounted thereon, the segments forming the screw conveyor substantially fitting the periph eral portions of the chamber and passages in which they are mounted. One end of the shaft I48 is mounted in a bearing I4 Ia, while the opposite end portion of the shaft is carried by the bearing relation of the screw conveyor sections in the chamber and passageway.

A propeller MI is mounted on the shaft I40 at the discharge end of the screw conveyor I42 within the narrow passage I45 to force the material therefrom into the molding device. Transverse bars or blades I43 (see Fig. 2) extend at right angles to the shaft I40 into the spaces between the sections of the conveyor I42. The bars or blades I 43 have sharpened edges to cut the material, causing thorough mixing of the asbestos fibers through the cement, and prevent lumping.

When the compression device is brought into alignment with the molding device 65, it is adapted to be secured directly to the end of the casing 66. A flange I46 on the casing I34 is secured to the end of the casing 66 by the screws 98, after removal of the door 94 and plate 92, and replacing the ring 9! by the ring I41 and a disc I49, in the relation shown in Fig. 1. Then upon the operation of the extrusion machine, the material is fed by the conveyor I42 therethrough and into the mold device 65 until the latter is filled with sufficient quantity to form the molded pipe. Then the extrusion machine is removed and the molding apparatus closed by the parts shown in Fig. 7, after which the hydraulic power device is operated to apply pressure by the piston I4 against the end of the formed pipe P to press the material and shape the pipe in the molding device.

The casing of the molding device has an outlet I54 for blowin out accumulations of material particles and foreign substance after the molding operation.

In the modified form shown in Figs. 3 and 4, the screw device is replaced by a reciprocating pressure device actuated by means of a hydraulic press. This hydraulic extrusion device includes a casing I50 which is preferably considerably longer than the casing I34 in Fig. 1, and is connected with the hydraulic actuating mechanism therefor, forming a rigid structure that is mounted to travel on three rails I5I. The casing I58 has a chamber I66 therein adapted to receive cementitious material from a. hopper I52. Rollers I 53 are operatively mounted in the hopper I52, and each roller has miter ribs I 54 on the periphery thereof arranged in coacting and interfitting relation with the ribs on the adjacent roller, whereby the rollers feed the material uniformly from the hopper through an opening I55 in the top of the casing I50, into the chamber I66 therein.

A piston I56 is operatively mounted in the chamber I66 on a piston rod I51 extending from the casing I50 into a second casing I58 that is connected with the casing I55 by tie rods in a rigid relation. A piston I59 is mounted on the end of the piston rod I51 in the casing I58 and constitutes the operating means for the extrusion device. Hydraulic pressure is imparted to the piston I59 through pipes I60 and IGI, extending respectively to opposite ends of the cylinder in the casing I58, and being controlled by a valve I62 connected with a source of hydraulic pressure through a pipe line I63.

The chamber I66 in the casing I50 is reduced at its discharge end I67 Where it opens into the molding device to increase the compression of the material as it is discharged from the extrusion device. The casing I50 has an outlet I68 for removing foreign substances therefrom.

In the operation of this device, the piston I59 is first moved to the position shown in dotted lines in Fig. 3, and the rollers I53 are operated to feed the cementitious material from the hopper I52 into the chamber I66 in advance of the piston I56. When this chamber is filled, the

hydraulic pressure is turned into the right hand end of the cylinder in the casing I58, forcing the pistons I56, I59, to advance as shown in full lines in Fig. 3. This action forces the material from the chamber I66 into the mold 65 around the mandrel mounted therein as described above to mold a pipe around the mandrel. Thereafter, the hydraulic pressure is reversed and turned through the pipe I60 to force the piStOns to the right in Fig. 3 to the dotted line positions shown therein, after which a new charge of material is inserted in the chamber I66. One or more charges may be used to supply material for each pipe, according to the relative sizes of the mold and charging chamber.

Provision is made in the apparatus shown in Fig, 7 for extracting the Water from the pipe by connecting a source of vacuum at one or both opposite ends of the cylinder 66. This connection may be made through the pipe at one end and the pipe 69 at the opposite end, which will facilitate drying of the formed pipe throughout its length. The water will pass out of the cementitious pipe through the perforations in the mandrel as described above.

Referring again to Fig. 7, attention is called to the provision of a blow out opening III, controlled by a slide valve II2, permitting particles of materials, or any foreign substances, to be blown out by opening the valve I3, so that water may flow between the piston I4 and the casing wall to escape through the opening I I I, carrying along the foreign substances.

Iclaim:

1. In apparatus for forming a pipe, the combination of an elongated compression chamber having an inlet at one end thereof adapted to receive a fibrous cementitious composition therethrough, said chamber having a cylindrical portion of smaller diameter than the chamber and connected at one end by a tapered portion therewith, said cylindrical portion having a discharge opening at the opposite end thereof for extrusion of the composition therefrom, and a screw mounted in the chamber for working the composition therethrough to the discharge end thereof, said screw having a thread portion of smaller pitch in said cylindrical portion than the thread portion thereof in the compression chamber.

2. In apparatus for forming a pipe, the combination of an elongated compression chamber having an inlet at one end thereof adapted to receive a fibrous cementitious composition therethrough, said chamber having a cylindrical portion of smaller diameter than the chamber and connected at one end by a tapered portion therewith, said cylindrical portion having a discharge opening at the opposite end thereof for extrusion of the composition therefrom, a screw mounted in the chamber for working the composition therethrough to the discharge end thereof, said screw having portions of different diameters in the compression chamber and cylindrical portion respectively, and knife blade means mounted in the chamber for imparting slicing action through the material during feeding of the material.

3. In apparatus for forming a pipe, the combination of an elongated compression chamber having an inlet at one end thereof adapted to receive a fibrous cementitious composition therethrough, said chamber having a discharge opening at the opposite end thereof for extrusion of the composition therefrom, a screw mounted in the chamber for working the composition therethrough to the discharge end thereof, a hopper arranged to supply material to the inlet opening, and operative feeding means for forcing the material from the hopper into the screw, said feeding means including coacting rollers having interfitting peripheral ribs arranged to force the material into the chamber.

4. In apparatus for forming a pipe, the combination of an elongated compression chamber having an inlet at one end thereof adapted to receive a fibrous cementitious composition therethrough, said chamber having a discharge opening at the opposite end thereof for extrusion of the composition therefrom, a mold shaped to form a pipe with a bell collar on an end thereof, means connecting said bell-forming end of the mold with the compression chamber at the outlet thereof, and extrusion means for forcing the composition from the compression chamber into the mold, said bell-forming portion of the mold being of appreciably greater diameter than the discharge opening from the compression chamher for expansion of the composition into the mold.

5. In apparatus for forming a pipe, a mold having an inner cavity, a mandrel within the mold, means mounting the mandrel in the mold spaced from the wall of the cavity including a ring surrounding an end of mandrel, said ring having openings therethrough about the periphery of the mandrel, pressure means at the opposite end of the mandrel and including means operating between the mandrel and the mold for imparting endwise pressure to the formed pipe on the mandrel.

6. In apparatus for forming a pipe, a mold having an inner cavity shaped to form the external surface of the pipe, a mandrel Within the mold and shaped to form the inner surface of the pipe, and means mounting said mandrel in the mold spaced from the wall of the cavity, said mandrel having perforations therethrough for draining moisture from the pipe to the interior of the mandrel, said mounting means including a ring surrounding an end of the mandrel and substantially closing the space between the mandrel and the mold cavity, and means for applying pressure against the opposite end portion of the formed pipe in opposed relation to said ring.

7. In apparatus for forming a pipe, a mold having an inner cavity shaped to form the external surface of the pipe, 2. mandrel within the mold and shaped to form the inner surface of the pipe, and means mounting said mandrel in the mold spaced from the wall of the cavity, said mandrel having perforations therethrough for draining the moisture from the pipe to the interior of the mandrel, said mounting means including a ring surrounding an end of the mandrel and substantially closing the space between said mandrel and the mold cavity, and fluid pressure operated means at the opposite end of the mandrel and arranged in relation to act lengthwise of the mandrel for applying endwise pressure to the formed pipe on the mandrel at a point between the mandrel and the mold cavity to compact the pipe and to force the moisture therefrom.

8. In apparatus for forming a pipe, a mold having an inner cavity shaped to form the external surface of the pipe, a mandrel within the mold and shaped to form the inner surface of the pipe, and means mounting said mandrel in the mold spaced from the wall of the cavity, said mandrel having perforations therethrough for draining the moisture from the pipe to the interior of the mandrel, said mounting means including a ring surrounding an end of the mandrel and substantially closing the space between said mandrel and the mold cavity, a piston slidably interposed between the opposite end of the mandrel and the mold, and means connected with the piston to move the same relative to the mandrel for compressing the material in the direction of the ring to compact the pipe and to force the moisture therefrom.

9. In apparatus for forming a pipe, a mold having an inner cavity shaped to form the external surface of the pipe, a mandrel within the mold and shaped to form the inner surface of the pipe, and means mounting said mandrel in the mold spaced from the wall of the cavity, said mandrel having perforations therethrough for draining the moisture from the pipe to the interior of the mandrel, said mounting means including a ring surrounding an end of the mandrel and substantially closing the space between said mandrel and the mold cavity, a piston slidably interposed between the opposite end of the mandrel and the mold, and means connected with the piston to move the same relative to the mandrel for compressing the material in the direction of the ring to compact the pipe and to force the moisture therefrom, and means connected with the mold at the periphery of the cavity adjacent opposite ends of the cavity for removing the moisture therefrom upon compression of the pipe.

JOHN FERLA.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 1,273,527 Norris July 23, 1918 293,000 Fate et al. Feb. 5, 1884 711,493 Gottschalk Oct. 21, 1902 1,858,956 Hepperle May 17, 1932 965,002 Pauly July 19, 1910 1,363,912 Pauly Dec. 28, 1920 1,875,738 Jones Sept. 6, 1932 2,144,213 Bassett et al. Jan. 17, 1939 1,026,887 Van Deventer May 21, 1912 1,072,495 Priest Sept. 9, 1913 2,030,758 Naturkaoz Feb. 11, 1936 FOREIGN PATENTS Number Country Date 363,873 Great Britain Dec. 31, 1931 162,082 Switzerland Aug. 16, 1933 

